You can add that second degree at any time before you actually apply for graduation. You can probably get away with adding after applying. It's anyone's guess when it would finally be too late. You could even delay applying if you needed more time to get the courses for the second degree, although I'd guess you'd have a solid month to get those transcripts in after the graduation application deadline.
NanoDegree: Intro to Self-Driving Cars (2019)
Coursera: Stanford Machine Learning (2019)
TESU: BA in Comp Sci (2016)
TECEP:Env Ethics (2015); TESU PLA:Software Eng, Computer Arch, C++, Advanced C++, Data Struct (2015); TESU Courses:Capstone, Database Mngmnt Sys, Op Sys, Artificial Intel, Discrete Math, Intro to Portfolio Dev, Intro PLA (2014-16); DSST:Anthro, Pers Fin, Astronomy (2014); CLEP:Intro to Soc (2014); Saylor.org:Intro to Computers (2014); CC: 69 units (1980-88)
PLA Tips Thread - TESU: What is in a Portfolio?
Coursera: Stanford Machine Learning (2019)
TESU: BA in Comp Sci (2016)
TECEP:Env Ethics (2015); TESU PLA:Software Eng, Computer Arch, C++, Advanced C++, Data Struct (2015); TESU Courses:Capstone, Database Mngmnt Sys, Op Sys, Artificial Intel, Discrete Math, Intro to Portfolio Dev, Intro PLA (2014-16); DSST:Anthro, Pers Fin, Astronomy (2014); CLEP:Intro to Soc (2014); Saylor.org:Intro to Computers (2014); CC: 69 units (1980-88)
PLA Tips Thread - TESU: What is in a Portfolio?